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A low-matrix-ratio [Nb.sub.3]Al wire is fabricated and the effects of the rapid heating/quenching (RHQ) current and the area reduction (AR) after the RHQ process are studied. The studies have shown that the optimum RHQ current to obtain high [J.sub.c] is the current at the higher edge of the plateau region and the AR process has affected the transformation process that has determined the quality of the A-15 phase.

A 2-dimensional calculation code is made for a stress-strain analysis and the stress and strain of the magnet is derived from using some physical values. The studies have shown that the [Nb.sub.3]Sn conductors are fit for high-magnetic-field and large-scale magnets such as NMR and SMES magnets.

The closed electric circuit concept is used for critical current and stability measurements of [Nb.sub.3]Sn multi-strand superconducting cables. Significant degradation is observed in the critical current of the cable when the average compressive stress is about 20 MPa, which is found to be irreversible after unloading.

The article examines the degradation due to transverse loading under high magnetic field. Findings reveal an irreversible degradation due to compressive stress of around 30 MPa.

The study investigates the dependence of the AC losses on the tensile stress in various conductors that are coated with high temperature superconductor (HTS) and have various magnetic substrates. The characteristics are found to depend on the recovery of critical current after the release of the stress.

The synthesis of new [Nb.sub.3]Al wires with high critical current density and improved fabrication parameters, such as the heat reduction ration is being discussed. The wires exhibit conducting properties and hence can be widely used for future accelerator magnets.

AC transport current loss was analyzed and measured in BSCCO tape in the external magnetic field.

A model was used in numerical investigations in the properties of the inter-layer current distribution and AC losses in co-axial multi layer cable conductors with superconducting magnetic shields.

A study of the development trends in magnet technology in Japan, conducted using the data base compiled by the Institute of Electrical Engineers of Japan, is presented. The data base is composed of information on low temperature superconducting magnets developed in Japan from 1988 to 1998. The investigation focuses on the configurations and sizes of the developed magnets, the conductor configurations and the current density of magnet windings.

A five-kilo-volt-ampere prototype of a superconducting linear induction motor (SLIM) for use in steel mills is introduced. The SLIM, which consists of six D-shaped coils wound from multifilamentary Cu/CuNi/NbTi superconducting wire, demonstrated growth of a normal zone at phase U currents above 72 A. This is probably due to the large losses induced at the joints of the current leads and the superconducting cables.

We are developing a 4 pole 50 Hz 30 kVA class fully superconducting generator to investigate the characteristics of superconducting armature windings subject to a rotating magnetic field. Compared with other fully superconducting generators that have been developed and tested, our machine is designed to obtain a higher armature current. It is generally observed in coils wound from AC superconducting cable that the AC quench current of the coil is much lower than its DC quench current. Countermeasures against these AC current degradation phenomena were developed and applied to the AC cable and armature winding of our generator. In the paper, results of the electrical tests of the generator are presented and the validity of the countermeasures is discussed.

The large helical device, a machine developed for Japan's National Institute for Fusion Science, contains helical coils whose windings are made of superconducting wires. A frictional force exists as a support between the conductors and spacers which is a function of the contact force. The latter, meanwhile, is a variable function of conductor bending and spacer dimensions. An experimental study sheds more light on the phenomena.